Telephone unit



March 13, 1945. c. s. LINELL TELEPHONE UNIT Filed Jan. 26, 1942 PatentedMar. 13, 1945 f 3 r T EEP Q EUNII I CharlsS ll inelliDakllark illanssignon to'Frank i .crnem s m AppIicationJ'anuany-QG, 1942SerialNoi-428,'181" Y sessile; (cris s- 114,) v p a This inventionrelate to telephone unit's, pie l'yin'g' the diaphragm. The cover has anu mh'er ticularly telephone receivers 'It the "of the of holes orperforations through which sound objects of the present inventiontoprovide "a may pass to: or: from the diaphragmxas'isusual telephonereceiver which can 'bemade 'exceedin telephone receivers. Thecasin'g 2is illustrated ingly thin and light in weight'wherhy thesame a morefully "in Figures 5 and 6 andconsists'of-a is adapted" to be mounted ina helmetsuch asds havinga peripheral rim 81 The h'ott'o'mo'f worn byaviators andth'ef like. It'ifs a further theca'sing' 2 isof reducedthickness to form two object ofithepresent' invention to provides;televertical'walls HT-and H rising from the base- '1 phone "unit which.is rugged in construction and toforma shallow trough extending acrossthe yet"ofgreat-sensitivity -in proportion to its rweight'; 10 casing;These walls terminate" in ledges 12 12.

It" is: a still further object of" the presen in- Terminal plugs m m ofbrass orthe like are Ventiorrtoprovide a telephone unit which' is,sinimolded in the casing. at the time of 'nranuiactjure pie. inconstruction, efiicient, and reliable iii-its thereof: Thereafter (oreven during; themold operation, light in weight and economical of mg)twoho1es at right anglestooneanotherare manufacture; l5 fonned from therim 8 toa'each terminal plug;

The attainment? of the above andyfurther'ob- Qneof-theseholes; indicatedat P5} isforreceiv facts of the present invention will be" apparent inga line conductor which extends into a Bore from thefollowingspecification takenin' con in the terminal. The other hole,indicatezi v at junction with the accompanyin drawingiorm: F6, is forreceiving a screw that threads into inga part-thereof; 2'0 thefterminalplug-and presses against" the tip'--ojf Inth-e drawing p I a conductorinsertedthereint'othrough thehole Figure 1 is: aperspective view' of atelephone F5; thereby establishing-good electric conductivit'g'i unit"embodying the principles of the presentinbetween the'bared end-of "theconductor andthe ventionr terminal plug. The bottomoutside surfaceofFigurezis atop viewiof the unitiwith the-cover th -'ca;sing has-twoconductor receiving grooves thereofremoved';- I l'T-'l-1*in*line-"withthe holes l-5 l-5{ Spacers Figure 3 is a transverse-sectionalview taken B i9 are int'egral with and. extend upwardly along the line3--3 of- Figure 2 and" looking" in fronrthe base? fora purpose'whiohwillhe 'a'p the direction-of the arrows; parent asthis descriptionproceeds.

Figure 4 is a sectional view taken along" the "Themagnetic structure forthe telephone unit line 4-4 Of'Figure-"Z-end lookingin thedireccomprises twoidenticaF'soft iron bars Z-D -ZI of tion ofthe arrows; Iaconstruction such as shown more fully iirFig Figure 515 a topviewof-thecasing of'Figure Z ure 9Q Each-of these bars is formed of" a soft withthe electrical mechanismremovedthere iron-stamping of a generallyT'-shape-, with the from: stem of the Tpent upwardly; as indicaitedf-atFigure 6' is a sectional view taken along-the. 2 2 23, to'constitutecore's forreceiving the usual lined- 6 ofFigure-Sj telephone unitwindings. These cores 22 23 are Figure? is a' perspective viewofthemagnetic integral parts of the bars- 20" and" 21- respectively;structure of the telephone unit; The-softironbars-ZO and 2'! are laid onthehase Figure 81s a perspective'view' ofthe clamp used 40 1'-Between-the spacers i8 and I9 which thus ass-- for-securing themagnetic-structure in place; sure thesepa'ration-of the bars 20 and 2|?from Figure 9' is -a-'perspective' view of two-iron bars one another.Powerful'permanent magnet bars constituting a part oftlie" magneticstructure" of 25 -23 are then laid across thebarszo z l The theunit;"andY i magnets overlie thespacers lB-IB andrestupon F'i urelflisa'persbective-viewof oneoftliebar 4 the"bars-2ll 2'l. 'The magnets 2-5-46 are posimagnet'sof-Figure'l; tionedover thebars 20-2! sotha't likepoles a're Reference may'now'be' had more partic larly positionedover-the same bar. AS illustrated? to the drawing wherein' like"reference numerals the north polesofthe two magnets are 'over' anddesignate like-parts throughout; I in contact with the bar 20 whereasthe south Theteleplione' unit of the present invention is 50 poles ofthe two magnets are over the bar'Z-IZ indicated at land is era generallycirculanshape: Thus both magnets are connected in parallel; Itconsi'st'sofa shallowopentop circular-casing andinithe embodiment hereillustratedthe-corej f'ofl'molfied'insulatingjmaterial withinwhich' the ZZ isanorth pole and the core- 23 i a southelectricaiipartsarecontained;,agthimflexibieteiepole. Anon-magneticclamp is'then' mountedto" phone diaplnagm-3't1 ig:"3)"; and-a cover l-over hol'dtfie' magnetic structure inplace: Therciampconsists of astrip of brass or other non-magnetic metal, having a bottom portion 3!which rests on the base 1 between and parallel to the soft iron bars-21. The bottom 3| is bent to form two inverted U-shaped hooked portions32-33 which embrace the bar magnets -26. A screw 34 is inserted througha hole in the clamp 3t the head of the screw resting in a countersunkhole in said clamp. A nut 36 threads on the shank of the screw 34 on theoutside of the casing. Upon tightening of the nut 36 the screw draws theclamp firmly against the base 1 and thus firmly holds the magneticstructure in place. V A pair of wound metallic coils 38-39 havingrectangular holes therein of a size corresponding to that of the cores22-23 are then slipped overthe cores, upon which they fit snugly. Thetwo coils 38-39 are electrically connected in series. The lead wires ofthe two coils are connected respectively to the terminals l4-l4 in anydesired manner.

The thin metallic telephone diaphragm 3 rests a non-magnetic securingclamp extending across the magnets and between the cores and securedupon the top of the peripheral rim 3 and is spaced slightly from thecores 22-23. The nonmagnetic cover 4 is made very thin and is preferablyof light metal such as, for instance, aluminum. The cover has aperipheral flange or rim 40 which closely embraces the rim 8. The rim 8is provided with a small shoulder at 4| extending around the entireperiphery of the unit. The edge of the flange or rim 40 is spun orpressed inwardly, as indicated at 42, to secure the cover in place. Thecover bears against the telephone diaphragm 3 only along the rim 8 andis spaced from the diaphragm along the rest of the area of thediaphragm, as may be seen from Figures 3 and 4.

Line conductors for extending the circuit to the telephone unit areindicated at -43. These are insulated conductors having a bared tip. Thetip 46 of each conductor isinserted through one of the holes 15 into ahole in'the associated terminal l4 and is then secured in place by a,screw 48 that extends through the hole 18 and threads into the terminal14 and presses the bared tip of the conductor into firm engagement withthe terminal. The metallic tip 4 5 which is secured to the end of eachconductor 45 terminates in the groove I1 and is held in the. groove H bythe screw 48. The insulation on the conductor 45 at the point where theconductor is secured to the tip 46 also lies in the groove I! and thusis not subject to bending action, thereby prolonging the life of theconductor. In compliance-with the requirements of the patent statutes Ihave here shown and described a preferred embodiment of my invention. Itis, however, to be understood that the invention is not limited to theprecise construction here shown, the same being merely illustrative ofthe principles of the invention. V What I consider new and desire tosecure by Letters Patent is: I

. l. In a telephone unit, a pair of spaced parallel soft iron bars, apair of magnets overlying the bars at the ends thereof, means forholding the magnets in position on thebars, saidmeans comprising anon-magnetic mounting spaceribetween the bars and substantially at thesame level as that of the base of the bars and having upstanding hookportions at the ends thereof overlying the magnets and holding them inplace, each of said bars having acoil-receiving magnetic 1 core integraltherewith: and extending to the bottom of the casing, and telephonecoils embracing the respective cores and overlying the securing clamp.

' 3. A magnetic structure for a telephone unit, said structurecomprising two side by side parallel soft iron bars each having awinding-receivin'g core integral therewith and projecting therefrommidway between the ends thereof, and permanent magnets bridging the twobars at opposite ends thereof, said magnets being magneti cally, inparallel across the two bars, and a nonmagnetic clamp between the barsat the level of the bars and. bearing against the magnets for securingthe magnetic structure in place.

4. A magnetic structure for a telephone unit, said structure comprisingtwo side by side mag,- netic bars each having a, winding receiving'core'integral therewith and projecting therefrom midway between the endsthereof, permanent magnets bridging the two bars at opposite endsthereof, each core being at right angles to and be tween both magnets, anon-magnetic clamp 'embracing both magnets and extending from one magnetto the other between the bars and at the level of the bars, and coils onthe cores with the bottoms of the coils substantially on the bars.

5. A magnetic structure for a. telephone, said structure comprising twoside'by side bars of magnetic material having winding-receiving coresintegral therewith and extending upwardly therefrom intermediate theends thereof, a per-v manent magnet overlying adjacent ends of, thebars, a second permanent magnet overlying the ends of the bars oppositethe first mentioned ends, a non-magnetic clamp between the two bars,said clamp comprising aometal stripthe net overlying adjacent ends ofthe bars, a sec.

ond permanent magnet overlying theends of the barsopposite the firstmentioned ends, a nonmagnetic clamp between the two bars, said clampcomprising a metal strip'the ends of which are bent to form invertedU-shaped brackets .embracing the respective magnets and clamping themtowards the bars, means atthe center of the bracket forsecuring thebracket in place in;

the casing,magnetic windings'on the cores, te'rminals embedded in thecasing on opposite sides of and spaced from the trough and making aliq!v uid-tight sealing fit inthe casing, said findings receiving coreintegral therewith and projecting I therefrom between the ends thereof,permanent magnets bridging the two bars at the opposite ends thereof, a,non-magnetic clamp on the base of the trough between the bars andextending across the magnets for holding the magnets in place on thebars, and means securing the clamp to the base of the trough of'thecasing.

8. A telephone unit having a shallow open casing of non-magneticmaterial and having a peripheral rim, a rectangular trough in the baseof the casing on the inside thereof, the portions of the bottom of thecasing between the trough and the rim forming ledges on opposite sidesof the trough, a rectangular magnetic structure within said trough andcomprising two side by side parallel soft iron bars each having awindlug-receiving core integral therewith and pro-' -jecting therefrombetween the ends thereof, permanent magnets bridging the two bars at theopposite ends thereof; a non-magnetic clamp on the base of the troughbetween the bars and extending across the magnets for holding themagnets in place on the bars, means securing the clamp to the base ofthe trough of the casing,"

coils on the cores, and terminals embedded in the ledges and sealedtherein, said ledges having line wire receiving holes extending thereinfrom the terminals to the outside of the casing.

CHARLES S. LINELL.

